Waterless condensing system for refrigerants



April 27, 1954 J A, wHlTE 2,676,791

- WATERLESS CONDENSING SYSTEM FOR REFRIGERANTS Filed Feb. 12, 1951 IN V EN TOR.

Patented Apr. 27, 1954 UNITED STATES PATENT OFFICE WATERLESS CONDENSING SYSTEM FOR REFRIGERANTS John A. White, near Golden, Colo. Application February 12, 1951, Serial No. 210,447

3 Claims.

This invention relates to a method and means for condensing the refrigerant in refrigerating plants, and has for its principal object the provision of a liquid cooling and condensing system which will eliminate the necessity for the use of water as a heat exchange medium, and which will provide a more eflicient heat exchange than is possible with the present water cooling systems.

Another object of the invention resides in the employment of a cooling medium of a type which will be expanded to a gas by the heat absorbed from the refrigerant, and which can be cooled below its boiling point by expansion and radiation to the atmosphere so that advantage may be taken of the cooling effect of latent heat of vaporization, which is impossible with water as a cooling medium.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efficiency. These will become more apparent from the following description.

In the following detailed description of the invention, reference is had to the accompanying drawin which forms a part hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.

In the drawing:

Fig. 1 is a diagrammatic flow sheet illustrating the improved refrigerant cooling system; and

Fig. 2 is a fragmentary, detail view, illustrating the construction of a refrigerant condenser employed in the improved system.

The improved system makes use of the well known fact that a chemical compound having a vaporization temperature of medium degree can be more easily condensed from a gas into a liquid than a chemical compound having a lower boiling point. In this improved method of cooling refrigerants, chemical compounds are employed having a medium boiling point, that is, in the range of from F. to'70 F. at atmospheric pressure. Such compounds include ethyl chloride, butane, iso-butane, and some Freons. In the following description of the improved method such a compound will be referred to as the cooling medium. It is to be understood, however, that other elements or compounds having boiling points between 10 F. and 70 F. would be satisfactory.

In the improved system the gaseous cooling medium is condensed to a liquid by absorption of heat therefrom through the medium of air, and the condensed liquid is then employed as a coolant for the refrigerant. The heat absorbed from the refrigerent vaporizes and gasifies the cooling medium, and the latter is then cooled by expansion, and through heat exchange with air, to return it to its original liquid condition for re-use in cooling the refrigerant. In other words, the ethyl chloride or other cooling medium replaces the water usually used in the refrigerant condenser for absorbing heat from the refrigerant, and due to the fact that the improved cooling medium expands to a gas while absorbing heat from the refrigerant, and contracts to a liquid during its cooling cycle, it provides a much more efficient coolant medium than Water.

A method of using the improved system is diagramrned in Fig. l in which a refrigerant condenser of special construction is designated in its entirety by the numeral Hi. The condenser comprises a continuous inner tube H which is jacketed through the major portion of its length by means of outer tubes 12. The outer tubes I2 are connected in series at staggered extremities by means of connecting tubes I3 to provide a continuous flow through the outer tubes throughout the condenser. The outer tubes 12 are preferably provided with suitable heat-radiating fins, as indicated at 41.

The refrigerant to be condensed, or other elements to be cooled, enters the condenser it through an intake pipe [4, and after passing in. sequence through all of the inner tubes ll, it discharges from the condenser through a discharge pipe 15 controlled by means of a suit able valve [6.

The ethyl chloride or other cooling medium enters the lowermost outer tube 12 from a liquid coolant pipe I1 controlled by a suitable valve l8, and after rising through all of the outer tubes l2, in sequence and in a direction opposite to the flow of the refrigerant, it discharges .through a coolant gas pipe ['9 controlled by a suitable valve 20.

The condenser It may have any construction which will accomplish the desired heat exchange results shown at it. Such a construction is illustrated more in detail in Fig. '2 in which the outer tubes I2 are welded, soldered, or otherwise sealed at their extremities to the inner tubes, as indicated at 2|. The outer tubes extend along the inner tubes H in concentric spaced relation thereto to provide a relatively close, cylindr'ical jacket about the major portion of the lengths of the inner .tubes II. The cooling medium enters each tube 12 at one extremity through one of the connecting tubes l3, and discharges from the opposite extremity through a second connecting tube l3.

The coolant gas pipe l9 conducts the coolant gas through a control valve 22 to the top of an expansion tank 23, which is preferably provided with cooling fins 24 and with internal air tubes 25 extending throughout its length. The tank 23 is enclosed in an air jacket 26 through which air is drawn or forced in any desired manner, such as from a blower 21, through an air conduit 28.

A float valve 29 is positioned in the tank 23 and controlled by means of a suitable float 30 to maintain a predetermined liquid level, indicated at 3 l in the tank.

The uncondensed gas and vapor from the tank 23 is conducted through a vapor pipe 32, controlled by a valve 33, to air-cooled condenser tubes 34. The tubes 34 are preferably provided with heat-radiating fins 35 and are arranged within an air jacket 36 which receives cooling air from the conduit 28, or from any other suitable source. The air flow removes suificient heat from coolant gases and vapors to return the cooling medium to its original liquid state, and the latter liquid drains from the tubes 34 through a drain pipe 31, controlled by a valve 38, to a liquid receiver 39. The liquid receiver 39 is preferably also enclosed in a cooling air jacket Ml, which may receive its air from the conduit 28. The receiver may be provided with cooling fins (not shown) should additional radiation be found desirable at this point. A second drain pipe M conducts the liquid cooling medium from the float valve 29 to the liquid receiver 39. The liquid cooling medium returns to the condenser it through the coolant liquid pipe 11.

The condensed refrigerant may be conducted from the condenser Hi through the discharge pipe IE to any desired position, such as to the expansion valve of the refrigerating system. As illustrated, the condensed refrigerant is conducted to a refrigerant receiver 42, from which it is drawn through a refrigerant return pipe 43 controlled by a suitable valve 44. It is preferred to also enclose the refrigerant receiver 42 in an air jacket 45 receiving forced air through a conduit 46 from the blower 21 or from any other suitable source.

The liquid cooling medium flows by gravity from the receiver 39 through the liquid pipe I? and enters the lowest outer tube of the refrigerant condenser l near the place where the condensed refrigerant discharges through the discharge pipe E5. The cooling medium and the refrigerant travel counter-current through the condenser Ill so that the coolest refrigerant continually passes the coldest cooling medium as it flows upward through the condenser. As the cooling medium absorbs heat, it will constantly encounter warmer refrigerant, but at all times throughout the entire condenser the COOIlng medium will be at a lower temperature than the adjacent refrigerant so that a cooling action is exerted throughout the entire height of the condenser 10. Thus, a continuous and highly efiicient action is obtained which simultaneously raises the cooling medium to its boiling point and chills the refrigerant to its liquefying oint.

The cooling medium discharges as a gas through the coolant gas pipe it under the pressure of the thermal expansion in the condenser l0 and discharges into the expansion tank 23 in a gaseous condition. The tank is, of course, cooled by the air flowing through the jacket 26 and through 4 the tubes 25 to a temperature below the boiling point of the coolant. This, together with the expansion of the gas into the large tank area, will condense a portion of the gas back to its liquid state, and the latter will collect at the bottom of the tank 23 until the liquid level 3! is reached, when it will be discharged as a liquid to the liquid receiver 39.

The remaining gas and vapor will flow to the condensing tubes 34, where they will be subjected to still further cooling from the air circulating through the jacket 36 and the fins 35. This will bring the remainder of the cooling medium to its original liquid stage and return it to the receiver 39, thus completing the cycle of the cooling medium.

The expansion tank 23 serves several purposes. First, it provides space for sudden expansion of the compressed cooling medium, thus resulting in an initial cooling action. Second, it subjects the gas to a heat exchange with air flowing from the conductor 28. Third, it expands the gas in intimate contact with liquid coolant in the bottom of the chamber, and it is well known that any gas will condense more readily in the presence of its own liquid than it will in a dry chamber.

It is preferred to install the expansion tank 23 and the cooling medium condenser coils at a higher elevation than the liquid receiver 39 so that the coolant will flow by gravity to the receiver. It is also preferred to install the condenser It! at a lower elevation than the receiver 3t so that the coolant liquid will flow by gravity to the lowest point of the condenser iii. The coolant will then be returned to the high point of the system by the thermal expansion generated by the heat exchange in the condenser it, so that pumps or other mechanical circulating equipment will not ordinarily be necessary, but could, of course, be used if required.

By eliminating the use of water, the constant cleaning necessitated by the formation of scale, corrosion, rust, etc., are entirely eliminated with this improved process. Since the coolant is in a completely closed circuit, no replacement is necessary.

While a specific form of the improvement been described and illustrated herein, it is to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent 1. Means for condensing a vaporized refrigerant, comprising: a refrigerant condenser ineluding a tube having a vaporized refrigerant receiving end and a condensed refrigerant discharge end, a jacket surrounding the major DOT" tion of the tube open from one end to the other, a conduit for conducting a liquid cooling medium into the end of said jacket adjacent the condensed refrigerant end of said tube, a conduit for conducting said cooling medium in a vapor form from the end of said jacket adjacent the vaporized refrigerant receiving end of the tube, first and second cooling medium vapor condensers with the first of which said last conduit is in communication, a conduit in communication with said first and second condensers, said first and second condensers each including an air jacket, a liquid cooling medium receiver with which said first conduit is in communication, a drain pipe at the lower end of each of said first and second condensers in communication with said liquid cooling medium receiver, a jacket surrounding said receiver, and means for forcing air through each of the jackets of said first and second condensers and said liquid cooling medium receiver.

2. The structure according to claim 1, where-'- in said tube is of sinuous form and embodies a plurality of spaced parallel sections and said first jacket comprising an elongated tube surrounding each of said sections, said last tubes being of greater diameter than said tube sections and being in communication by means of relatively short tubes connecting the ends of adjacent ones thereof alternately at the opposite ends thereof, and said last tubes having their opposite ends closed on said tube sections.

3. The structure according to claim 1, wherein said first cooling medium condenser comprises a tank provided with cooling fins, said cation with the jackets.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,808,494 Carney et al. June 2, 1931 1,922,091 Hull Aug. 15, 1933 2,145,692 Jones Jan. 31, 1939 2,181,354 Winters Nov. 28, 1939 2,250,648 Phillip July 29, 1941 2,323,511 Baker July 6, 1943 Y 2,336,066 Cain Dec. 7, 1943 2,344,214 Pownal Mar. 14, 1944 

